Ore-roasting furnace



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' R PEA ORE ROASTING NACB. No. 488,797. Patented 1360.27, 1892.

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PEARCE. v ORE ROASTING PURNAOE.

No. 488,797. Patented Dec. 27, 1892.

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r R. PEARCE! ORE ROASTING FURNACE.

No. 488,797. Patented Dec. 27., 1892.

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(No Model.) 4 Sheets-Sheet 4.

R-.PEARCE. ORE RQASTING PURNAGB.

Patented Dec. 27 1892.

Jrweniar UNITED STATES PATENT Trice.

RICHARD PEARCE, OF DENVER, COLORADO.

ORE-ROASTING FURNACE.

SPECIFICATION forming part of Letters Patent No. 488,797, dated December 27, 1892.

Application filed July 20, 1892. Serial No. 440,632. (No model.)

To all whom it may concern:

Be it known that I, RICHARD PEARCE, a subject of the Queen of Great Britain, residing at Denver, in the countyof Arapahoe, in the State of Colorado, have invented a certain new and useful Improvement in Ore-Roasting Furnaces, of which the following is a full, clear, and exact description.

The object of this invention is to provide a furnace for desulphurizing and chloridizing ores and mattes, in which the mass of material is constantly stirred and also progressively moved from the inlet to the outlet.

In carrying out my invention, I makeuse of a turret-like annular furnace, having one or more continuous annularhearths, and a series of arms radiating from a common center and carried around so as to sweep the hearth or hearths from inlet to outlet, to move the ore continuously and progressively. These arms are provided with a series of rabbles to stir the ore while it is in motion,and they are made hollow, and supplied with cool air to reduce their liability of burning out, the air being supplied also to the rabbles for a like purpose, and escaping into the furnace and being heated to supply oxygen for calcination.

Having thus stated the principle of my invention, I will proceed now to describe the best mode in which I have contemplated applying that principle, and then will particularly point out and distinctly claim the part or improvement which I claim as my invention.

In the accompanying drawings, illustrating my invention, in the several figures of which like parts are similarly designated, Figure 1 is a partly sectional plan view of portion of the furnace. Fig. 2 isa vertical cross section. Fig. 3 is a partly sectional plan view of the entire furnace. Fig. 4 is a Vertical section, on a larger scale, of the center column and the rotating head carrying the radiating arms. Figs. 5 and 6 are respectively a cross section and an elevation of one of the arms and rabbles and air feeders and showing the air feeders partly in section. Fig. 7 is a transverse section at the mouth of the furnace and Fig. 8 is a longitudinal section through the discharge-slot of the furnace. Fig. 9 is a plan view and Fig. 10 a sectional elevation illustrating the slot-guard, Fig. 11 is a sectional elevation of the left hand side of a double or two-hearth furnace. Fig. 12 is a front View showing details of the door, and Fig. 13 is a top view of the door.

The furnace is composed of an outer annular wall a, built up of red brick or other suitable material and a corresponding inner concentric wall I), of like material; and between these walls there is a filling c, of suitable material upon which is laid the hearth d, and this hearth is composed of fire brick or other refractory substance.

6, is the arch or crown of the furnace sprung from skew-backs a and b on the outer and inner Walls respectively. The outer wall is provided with wrought iron or other hands a and a to resist the thrust, respect ively of the hearth and arch. The inner wall I) is made with a continuous slot or opening f, just above the hearth; and the lower edge of this slot is protected by angle-irons g, while the upper edge, constituted of the skew-backs is suspended upon angle-irons h, which in turn are suspended by U-bolts i, which are supported by L beams j, and these I- beams rest, at their outer ends, upon shoes is, mounted upon the outer walla, and are supported at their inner ends upon brackets Z, which are mounted upon a central hollow column m. Obviously, the I-beams j, maybe arranged otherwise than as just described and as shown in the drawings, in order to accomplish the purposes for which they are intended, but as shown, the said I- beams not only serve to support the skew-backs of the inner wall but they also serve to stay the hollow column m from which, as shown, they radiate. The skew-backs and the hollow column may be further braced and supported by means of struts n made fast to the angleirons h and the hollow column, and radiating from the said hollow column. Fire-places 0 of suitable number and disposition are connected with the furnace, and the gases and other products of combustion are carried off through an opening 0 in the crown, as shown in dotted lines Fig. 3, to a dust-chamber 0 and thence to the stack 0 The ore to be treated is fed into the furnace in any suitable manner through an opening 19, (Fig. 3),in the crown, and the roasted ore is discharged from the hearth through an opening q in said hearth at the mouth g of the furnace. This month of the furnace is adapted to receive a car, corve or hutch g for removing the roasted ore, which car may be run into and out of the mouth underneath the discharge opening g on rails provided for that purpose. On each side of the mouth of the hearth a transverse door or guard r is provided, which is adapted to swing freely in the direction of motion of the stirrer-arms, hereinafter referred to, and to close automatically after said arms have passed, so as to prevent the undue loss of heatsee details in Figs. 3 7, 12 and 13. The door is shown as hung in bearings r and "r suitably supported in the masonry. The invention, however, is not limited to these details. In case one of the I-beams j should be arranged over the mouth g its end may be supported upon a bar or beamj which spans the said mouth and is supported upon shoes k on opposite sides of said mouth, as shown in Figs. 7 and 8.

By constructing; the furnace in the annular, turret-like form, I obtain a maximum length of furnace and a maximum exposure of the ore to be roasted in a minimum of space.

The stirrers before referred to are composed of hollow arms 8, which radiate from a common hub 3 which encircles the hollow column m. The outer ends 3 of these arms are made detachable from the inner ends and are connected therewith by couplings 8 which couplings are arranged outside the inner wall I). The ends 5 of the arms are provided with rabbles t, rigidly suspended therefrom, at about an angle of eighty (80) degrees with the axes of the said arms, and a suflicient number of these rabbles is attached to each arm to extend practically across the width of the hearth so as to cover the whole transverse area of the hearth. The hub s is made hollow and opposite the said hub the hollow col- 11 mu m is provided with openings m In connection with the said hollow columnis an air forcing apparatus (not shown) by which air, under pressure of one or more ounces, may be supplied to the said column. The sections-s of the arms are provided with outlets for the air, and by preference these outlets are made as tubes to, which extend downwardly behind the rabbles so as to supply air to them, whence it escapes into the furnace and serves for oxidizing purposes in the process of calcination. In order to close the space between the hollow column and the hollow hub 8 any suitable flexible covering may be employed, and I have shown bands of canvas 12, made fast to the column by metal bands c and having their outer ends provided with metal bands 1J3, resting upon the hub and held there in any suitable manner, as by springs 02 which springs may be fastened to the bands 11 but I do not limit my invention to any particular means for closing the space between the hollow column and the hub. The details of the connection of the hollow column and the hollow hub are shown more particularly in Fig. 4. As will be understood from the foregoing, the arms .9 project into the hearth through the slot f, and as will be understood also the outer ends 8 of these arms are exposed to the highest temperature and consequently the greatest wear; hence by making the said outer ends 3 detachable from the arms, they and the rabbles may be readily renewed as they are burned or worn out, without the necessity of disassembling the whole length of arms.

In order to close the slot against the escape of the heat and products of combustion, I provide a sectional shield 10, which is suspended from brackets 20 011 the couplings s and through which shield the arms 5 project into the furnace. This shield is curved to correspond to the curvature of the inner wall and is pressed up against the adjacent edges of the slot by any suitable means, as for instance, weighted bell crank levers w see Figs. 9 and 10. Of course this shield is carried around by the rotation of the arms.

The circular track 3 is supported in any suitable manner, as upon girders 11 borne by the inner wall and the hollow column: The couplings s are provided with wheels or rollers if, which move upon said track and support the arms upon such track. The arms are provided with a suspended toothed-ring z and this ring is guided and braced on the inside by guide rollers .2 which may be mounted upon the supports y of the track y. A pinion 2 is mounted upon a shaft 3 and engages the toothed-ring z, and this shaft 3 is connected by gearing 4 with a power shaft 5. Obviously, by the rotation of the pinion 2, the arms 5 will be rotated about the column on, and the rabbles will be caused to traverse the hearth in its entire circumference, taking in their course the ore from the inlet and progressively moving it and continuously stirring it from that point to the point of discharge.

As shown in Fig. 11, my improved furnace may be constructed in one or more stories, that is to say, the hearths may be arranged in tiers, or one above the other; and in such case the upper hearth will, by preference, be supported above the I-beams j, upon foundation plates 6,at1d arches 7. In order to trans mit power to the arms of the upper furnace, the lower furnace may have its toothed ring duplicated at 8, on the upper side of the arms, and this toothed ring 8 will be engaged by a pinion 9 on a shaft 10, which carries the pinion 2 of the upper furnace. The upper hearth may be entirely independent of the lower hearth, but usually there will be communication between them, so that the heat and products of combustion may pass from the lower to the upper, and the roasted ore from the upper may pass to the lower. If it be desired to drive the arms of the upper hearth in the direction the reverse of that in which the arms of the lower hearth are driven, then ICC instead of the outside.

one or the other of the toothed rings will be made larger and have its teeth on the inside It is apparent that with the same method of construction and the same transmission of power, any number of hearths may be built one above the other. Those parts of the double furnace corresponding with the single furnace as heretofore de scribed, are designated by the same reference characters.

What I claim is:

1. An annular or turret-like ore roasting furnace, composed of an inner wall having a horizontal slot, and an outer wall, a continuous hearth between said walls, an inlet for the material to be treated, and an adjacent outlet for the treated material, combined with stirrers or rabbles projecting into said furnace through said slot, and means to move said stirrers or rabbles continuously through said furnace from inlet to outlet,substantially as described.

2. An annular or turret-like ore roasting furnace, havinga continuous slot in its inner wall above the hearth, combined with arms extending through said slot into the furnace, over the hearth thereof and provided with -rabbles, and means to move said arms profurnace, having a horizontal slot in its inner wall just above the hearth, and hollow stirrer arms projected into said furnace through said slot, combined with a hollow hub in which all of said arms are centered, and a stationary,

hollow column having openings communicating with said hollow hub, and air-tight connections between the said hollow hub and hollow column, substantially as described.

6. An annular ore roasting furnace,having its inner wall slotted horizontally, combined with stirrer arms entering said furnace through said slot and composedof sections, couplings for uniting said sections, a supporting track, and rollers on said couplings running upon such track, substantially as described.

7. An annular ore roasting furnace, comprising an outer wall and an inner wall, the latter having a continuous horizontal slot, the upper edge of which is constituted of skewbacks for the crown of the furnace, angle-bars in which said skew-backs are supported, transverse I-beams and supports therefor, and bolts suspending said angle-bars from said I-beams, combined with stirrer-arms pro,- jecting into said furnace through said slot, and means to move said arms, substantially as described. 7

In testimony whereof I have hereunto set my hand this 16th day of July, A. D. 1892.

RICHARD PEARCE. Witnesses:

CRAWFORD HILL, FRANK REYNOLDS. 

